Power transmission



March 193s. 'E.-L .ROSEEFAL 2,1 9.782

POWER TRANSMISSION Filed Aug. 25, 1936 3 Sheets-Sheet 1 o W E Q 2,

INVENTORS. EDW/M L .IPosE BY Fksozwnr SHooomu ATTORNEY March 1, 1938.

E. L. ROSE ET AL 2,109,782 POWER TRANSMISSION Filed Aug. 25, 1936 l 5 Sheets-Sheet 2 INVENTORS Bnwuv L. Ross 8 If HLG BY I FFEDE/P/C/(SJWGMAN o z ATTORNEY.

March 1, 1938. s. 1.. ROSE ET AL 2,109,782

POWER TRANSMISSION Filed Aug. 25, 1936 I 3 Sheets-Sheet 3 Q Q: I k

8 3 9] .Q I l I N] l 3 =0 Q \9 \9 l a! Q a: Q

INVENTORS EDWIN L. Pass 8 BY FIPEDEIPICIISI/ODGMAN W X M ATTORNEY v Patented Mar. 1, 1938 POWER TRANSMISSION Edwin L; Rose, Watertown, Conn., and Frederick S. Hodgman, Glen Rock, N. J., assignors to The Waterbury Tool Company, Conn., a corporation of Connecticut Application August 25,

19 Claims.

This invention relates to power transmissions and particularly to transmissions of the' hydraulic type comprising a fluid pump and fluid motor either or both of which may be provided with mechanism for varying its displacement in order to vary the speed ratio between the prime mover which operates the pump and the load device which the motor operates; The invention is illustrated as adapted for use in a well drilling rig of well-known type in which a string of drill stem is caused to revolve by a rotary drilling head while a portion of the weight of the string rests upon the earth formation at the bottom of the hole being drilled, the remainder being suspended on l a block and falls mounted in a drilling derrick and connected to a draw-works drum.

It is desirable in such drilling operations to maintain at a constant valuethat portion of the weightgof drill string which rests upon the earth 20 formation at the bottom of the hole and to be able-to readily adjust such weight to diiferent values as different formations are encountered. Various systems have been proposed for automatically regulating the weight on the drill stem in such a manner. Systems of this character as heretofore constructed have utilized either the energy of the drill stem itself for feeding the same into the hole as required; such, for example, as systems wherein a friction or fiuid brake is aujtomatically regulated to maintain a constant tension on the draw-works drum, or have utilized an expensive and cumbersome power operated feed system such as a steam' or electric powered feed controlling apparatus. Devices of the latter class are not only expensive in first cost and in l operation but are open to other objections in that they require specially trained operators or are incapable of use in fields where an adequate wate 4 supply is not available.

It is an object of the present invention to propower for the draw-Works and other apparatus usually associated with drilling rigs of the rotary type and which small prime mover may preferably comprise a small internalcombustion en- Waterbury,

1936, Serial No. 97,792

gine of the type used in motor vehicles which are readily available at low cost.

It is a further object to provide a feed controlling apparatus for a well drilling rig wherein a hydraulic variable speed power transmission is incorporated for transmitting power between a substantially constant speed prime mover and the drawworks drum, whereby the speed of rotation of the drum may be precisely controlled automatically to maintain a predetermined constant weight on the drill bit and whereby also the-operation of the draw-works may be controlled manually as desired to either raise or lower the drill string at any speed within the power capacity limits of the prime mover.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a prefered form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a plan view partly in section of a well drilling rig showing a preferred form of the present invention.

Fig. 2 is a diagrammatic view of the hydraulic circuits incorporated in the apparatus illustrated in Fig. 1. i

' Fig. 3 is a vertical cross section on line 33 of Fig. 1 showing a hydraulic transmission forming part of the apparatus.

Fig. 4 isa fragmentary detail of a portion of the apparatus.

Referring now to Fig. 1 there is illustrated a draw-works haw/ing a drum Ill journalled in bearings I 2 and adapted to have wound thereon a cable by which a drilling string may be sup- "ported from a derrick, not shown, in the usual manner. The drum I0 is keyed to a shaft l4 on which is 'spline'd a slidable clutch member it which may be engaged either with a worm wheel It as shown in Fig. 1, or with a sprocket 20; The

sprocket 2ll is driven from a counter shaft 22 by means of a sprocket 24 and chain 26. The shaft 22 is journalled in bearings 28 and 30 and has keyed thereon a sprocket 32 which is driven by' means of a chain 34 from a suitable prime mover, not shown, through the medium of any suitable multiple speed transmission mechanism. Splined to the shaft 22 is a clutch member 36 slidable to engage a sprocket 38 loosely journalled on the shaft 22. Sprocket '38 drives by a'chain 40a sprocket 42 loosely mounted on the shaft M, the sprocket 42 being rigidly secured to a sprocket 44 :vnch drives a sprocket 45 by means of a chain The sprocket 44 is keyed to a shaft 48 which carries a bevelpinion 58 meshing with a bevel gear on the under side of a rotary table 52, whereby the drill stem may be given a rotary movement independent of the vertical movement imparted to it by the draw-works drum I8, as is well-known in the art. The apparatus thus far described is "Waterbury type, shown in Fig. 3. The pump 88 has an input shaft 82 which is connected by means of reduction gearing 84 to the crankshaft v of an internal combustion engine prime mover ton fluid motor 18. The conduit 12 has branches 88 and 82 communicating with ports 84 and 88 of a pressure responsive pilot valve 88 and a manually operable control valve 88 respectively. The return side of the pump circuit includes a return conduit 92 connected with an expansion tank 94 as well as with the interior of the casings of the pump 88 and the motor. 58. Branches 88 and 98 communicate with ports I88 and I 82 of the valves 88 and 88 respectively. Valve 88 has a third port I84communicating by means of a conduit I88 with a port I88 of a manually operable selector valve II8. while valve 88 similarly has a third port II2 communicating by means of a conduit II4 with a port II8 of the valve II8. A third port 8 of the valve II8 communicates by a conduit I28 with the large cylinder I22 of the fluid motor 18. A conduit I24 connects the conduits .14 and I28 and has disposed therein a check valve I28 opening toward the conduit". The usual relief valve I28 is provided between the outlet 12 and the inlet 82 of the pump 88 for the purpose of limiting the pressure developed in the conduit 12.

The valve 88 includes a movable valve member I38 which is secured at one end to a flexible diaphragm I32 forming a movable wall of a chamber I34 formed in the right-hand end of the body of the valve 88. A spring I38 abuts against the opposite end of the member I38 and can be adjusted by means of an adjusting screw I38. The

chamber I34 communicates by a conduit I48 with a chamber I42 formed adjacent the end of the worm 54. The latter carries at its right-hand end a shaft I44 with respect to which the worm 54 is free to rotate by means of ball bearings I48. Theshaft I44 is secured to a flexible diaphragm I48 forming a movable wall of the chamber I42. The conduit I48 includes a branch I58 leading to a pressure gauge I52 for indicating the pressure existingin the conduit 8.

Referring now to Fig. 3 wherein the internal mechanism of the variable speed transmission is illustrated; the pump 88 includes a revolving cylinder barrel I54 within, the bores I58 of which pistons I58 are re'ciprocated by the motion of a socket ring I 88 which revolves in. a tilting box I82. The tilting box I82 carries a stud I84 having a pivoting and sliding connection with the differential piston I88 of the fluid-motor 18. The

- socket ring I88 is caused to revolve with the shaft bores I58 due to the inclination of the plane in which the socket ring I88 rotates to the plane of the cylinder barrel I54, the stroke of the pistons I 58 being determined by the angular setting of the tilting box I82. As the pistons I58 are reciprocated, fluid is caused to be drawn into the cylinders I58 through one arcuate port, not shown, in the valve plate I12 and to be expelled from the cylinders I58 through the opposite arcuate port in valve plate I12.

The fluid motor 58 is similar in construction to the pump 88 except that the socket ring I88 is joumalled in a fixed angle box I82 rigidly secured to the casing I18 of the motor 58. Fluid delivered from the pump88 through the valve plate I12 is'admitted to the cylinders of the motor 58 causing the socket ring I88 and the shaft 58 to revolve while on the return stroke of the pistons in the motor 58, the fluid is returned to the pump through the valve plate I12. Customary replenishing and relief valves, not shown, are incorporated in the valve plate I12 for the purpose of maintaining the working circuit filled with fluid at all times and for preventing building up of excessive pressures and undue overloading of the machine. The construction and operation of hydraulic transmissions of this character are well-known in the art so that further descrip tion thereof is unnecessary.

In operation assuming the drill string to have been run into the hole and the apparatus arranged for drilling operation, the clutch member I8 having been adjusted to engage the worm gear I8 as illustrated in Fig. 1, and the clutch member 38 having been adjusted to engage the sprocket 38, the rotary table 52 is driven from the principal power source of the drilling rig through chain 34, sprocket 32,shaft 22, clutch 38, sprocket 38, chain 48, sprockets 42 and 44, chain 48, sprocket 45, shaft. 48 and 'bevel pinion 58. with the prime mover 88 running at a substantially constant speed, the shaft 58 will be caused to turn at a speed determined by the position of the tilting box I82 which is in turn governed by the position of the differential piston I88. Fluid under pressure delivered by the auxiliary pump 88 is transmitted throughthe conduit 14 to urge the piston I88 to the left in Fig. 2. The position of the movable member I38 of the valve 88 1s determined by the pressure, existing in the chamber I34 which inturn is determined by the reactive force exerted by the worm wheel I8 on the worm hssuming the cable to be wound on the drum in a direction in Fig. 2, such that the weight ofthe drill stem tends to turn the worm wheel I8 the worm 54 to the right thus increasing the pres sure in the chambers I42 and I 34. Assuming that the operations are started with the drill bit suscounter-clockwise, this weight consequently urges 2,109,782 force of the spring I36, permitting the valve I to move to the left and completely opening a passage between the ports I00 and I04. The piston is thereby caused to move to the left under the fluid pressure exerted in cylinder 16, the fluid in cylinder I22 being exhausted through the conduit I20, port 8, port I08, conduit I06,,ports I04 and I00 and conduit 96 to the return side of the system. The tilting box I62- thereby rotates in a counter-clockwise direction to the limit of its movement causing shaft 56 to revolve in a direction to rotate the worm wheel I8 and the drum l0 counter-clockwise in Fig. 2, thus lowering the drill string into the hole.

As soon as the drill bit touches the bottom of the hole, a portion of the weight of the drill string is supported on the earth so that the thrust of the worm 54 to the right in Fig. 2 is reduced. As soon as the reduced thrust reaches a value such that the spring I36 can overcome the thrust of the worm 54, the movable valve member I30 moves to the right sufficiently to close the port I00. Should the rate of downward feed of the drill stem be too great at this time, the thrust of the worm 54 is further reduced, thus permitting the valve member I30 to move further to the right and open the port 84 to communicate with the port I04. Fluid under pressure is thereby admitted to the cylinder I 22'through conduit H8, and conduit .I20 causing the piston I66 to 80, ports 84, and I04, conduit I06, ports I08 and move-to the right thus moving the tilting box I62 in a direction to decrease the stroke of thepistons I58,

As soon as the speed of the shaft 56 has been reduced sufficiently so that the downward movement of the drill stem is equal to the rate at which the drill bit makes hole, the thrust on the worm will come to a balance with the thrust exerted by the spring I36, thus permitting the valve I30 to move into the position shown in Fig. 2. Thereafter the drill string will be fed downwardly at the same rate so long as the bit "makes hole" at the same speed. As soon as any change oc- .curs in the rate at which the bit makes hole,

the thrust of the worm 54 correspondingly changes, causing the valve I 30 to make the required adjustments in the rate of feed of the drill stem.

"If for any reason, such as a failure of the principal power. supply of the drilling rig, it should be necessary or desirable to control the vertical movement of the drill string manually, the selector valve I I0 is shifted to the right in Fig. '2, thus connecting conduit I20 with the valve through conduit H4. The speed and direction of the draw-works drum I0 may thereafter be controlled by operating the valve 90. Thusfif it is I desired to decrease the speed in a downward direction or to increase the speed upwardly, the valve 60 will be moved to the right in Fig. 2, admitting fluid under pressure from the conduit 82, through ports 86 and II2,'conduit II4, ports-H6 and H8,

conduit I20 to the cylinder I22. The piston I 66 thereby moves to the right so long as valve is held to the right. Conversely, if the valve 90 is moved to the left, piston I66 moves to the left,

66 should fail, itis desirable to prevent damage to the rig being caused thereby; For this purpose springs I14 and I16 arepr'ovided in 'the substantially to zero.

spring I16 moves the piston I66 .to the left to' independently'of the controlling member.

cylinders I22 and 16 respectively. Whenever the piston I66 is to the right of mid-position, that'is,

whenever the dfiiw-works drum is being driven in a hoisting direction by the auxiliary prime mover 66, if any failure of the prime mover 66 5 should occur, the pressure in conduit 14 will drop Under these conditions mid-position, thus bringing the hydraulic transmission to a safe position where the weight of 10 during drilling operations, it is desirable to pre- 20 vent continued turning of the table 52 so as to prevent a twist-off. For this purpose the clutch 36 has its operating lever I18 biased to the right in Fig. 4 by a spring I80 and is held in clutch engaging position by a latch I82. A 25 piston I 84mounted in a cylinder I86 is biased to the left by a spring I88 and connected to the latch I82. The cylinder I66 is in communication with conduit 14 by a conduit I90. The con struction is such that the latch I82 is maintained in engagement with the lever I18 only when pressure of a predetermined magnitude exists inconduit 14; Whenever the pressure falls below this point the latch I82 is tripped by the'spring I88 thus permitting spring I80 to disengage clutch 36 and interrupt the rotation of table 52.

While the form of'embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. g

What is claimed is as follows:

1. In a well drilling rig .the combination of a drill string, a draw-works drum, a; prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, a controlling member movable in accordance with variations' in torque imposed on the drum by the drill string, a motor for varying the speed ratio -of the power transmission, and means whereby said controlling member may control operation of said motor.

2. In a well drilling rig the combination of a drill string, a draw-works drlim', aprime' mover,

a, variable speed power transmission connected,

3. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and ber may control operation or said motor, addi- 75 Obviously, if 15 tional manually controlled means for varying the speed ratio of the power transmission independently of the controlling member, and means for selectively rendering the transmission subject to control either by the controlling member or by the manually controlled means.

4. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variablespeed power transmission including a variable displacement pump and a fluid motor operable thereby connected in driving relation between the prime mover and the draw-works drum, a controlling member movable in accordance with variations in torque imposed on the drum by the drill string, a motor for varying the speed ratio of the power transmission, and means whereby said controlling member may control operation of said motor.

5. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission including a variable displacement pump and a fluid motor operable thereby connected in driving relation between the prime mover and the draw-works drum, a controlling member movable in accordance with variations in torque imposed on the drum by the drill string, a, motor for varying the speed ratio of the power transmission, means whereby said controlling member may control operation of said motor, and additional manually controlled means for varying the speed ratio of the power transmission independently of the controlling member.

6. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission including a variable displacement pump and a fluid motor operable thereby connected in driving relation between the prime mover and the draw-works drum, a controlling member movable in accordance with variations in torque imposed on the drum by the drill string, a motor for varying the speed ratio of the power transmission, means whereby said controlling member may control operation of said motor}additional manually controlled means for varying the speed ratio of the power transmission independently of the controlling member, andmeans for selectively rendering the transmission subject to control either by the controlling member or by the manually controlled means.

'7. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, additional means for driving said draw-works drum independently of said prime mover, a controlling member movable in accordance with variations in torque imposed on the drum by the drill string, a motor for varying the speed ratio of the power transmission, means whereby said controlling member may control operation of said motor, and means for selectively connecting said draw-works drum to be driveneither by the power transmission or, by said additional driving means.

'8. Ina well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, and means responsive to variations in torque imposed on the draw-works drum-for controlling the speed ratio of thepower transmission to feed the drill string downwardly its weight suspended by the draw-works drum. 9. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover,

a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, means responsive to variations in torque imposed on the draw-works drum for controlling the speed ratio of the power transmission to feed the drill string downwardly at a rate to maintain a constant proportion of its weight suspended by the draw-works drum, and additional manually controlled means for varying the speed ratio of the power transmission independently of the torque imposed on the drawworks drum.

10. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, means responsive to variations in torque imposed on the draw-works drum for controlling the speed ratio of the power transmission to feed the drill string .downwardly at I a rate to maintain a constant proportion of its weight suspended by the draw-works drum, additional manually controlled means for varying the speed ratio of the power transmission independently of the torque imposed on the drawworks drum, and means for selectively rendering the power transmission subject to control either by the torque responsive means or by the manually controlled means. a

'11. In a well drilling rig the combination of a drill string, a draw-works drum; a prime mover, a variable speed power transmission including a variable displacement pump and a fluid motor operable thereby connected in driving relation between the prime mover and the draw-works drum, and means responsive to variations in torque imposed on the draw-works drum for controlling the speed ratio of the power transmission to feed the drill string downwardly at a rate to maintain a constant proportion of its weight suspended by the draw-works drum.

12. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission including a variable displacement pump and a fluid motor operable thereby connected in driving relation between the prime mover and the draw-works drum, means responsive to variations in torque imposed on the draw-works drum for controlling the speed ratio of the power transmission to feed the drill string downwardly at a rate to maintain a constant proportion of its weight suspended by the draw-works drum, and additional manually controlled means for varying the speed ratio of the power transmission independently of the torque imposed on the draw-works drum.

13. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover,

between the prime mover and the-draw-works, drum, means responsive to variations in torque imposed on the draw-works drum for controlling the speed ratio of the power transmission to feed the drill string "downwardly at a rate to maintain a constant proportion of its weight suspended by the draw-works drum, additional manually controlled means for varying the speed ratio of the power transmission independently of the torque imposed on the draw-works drum, and means for selectively rendering the power transmission subject to control either by the torque responsive means or by the manually controlled means.

14. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, a controlling member movable in accordance with variations in torque. imposed on the drum by the drill string, a fluid motor for varying the speed ratio of the power transmission, and means including a valve operably connected to said motor whereby said controlling member may control operation of said motor.

15. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum,,a controlling member movable in accordance with variations in torque imposed on the drum by the drill string, a fluid motor for varying the speed ratio of the power transmission, means including a valve whereby said controlling member may control operation of said motor, and an additional manually operable valve for controlling the motor independently of said controlling member.

16. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, a controlling member movable in accordance with variations in torque imposed on the drum by the drill string, a fluid motor for varying the speed ratio of the power transmission, means including a valve whereby said controlling member may control operation of said motor, an additional manually operable valve for controlling the motor independently of said controlling member, and a selector valve for manually rendering said motor responsive either to,

said first valve or said second valve.

17. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed'power transmission connected in driving relation between the prime mover and the draw-works drum, a rotary table for. rotating said drill string, means independent of said prime mover for driving said rotary table, and means responsive to variations in torque imposed on the draw-works drum for controlling the speed ratio of the power transmission to feed the drill string downwardly at a rate to maintain aconstant proportion of its weight suspended by the drawworks drum, and means responsive to a failure of said prime mover for stopping said rotary table.

18. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, means responsive to variations in torque imposed on the draw-works drum for controlling the speed ratio of the power transmission to feed the drill string downwardly at a rate to maintain a constant proportion of its weight suspended by the draw-works drum, and means responsive to a failure of said prime mover for preventing said drill string from dropping into the hole.

19. In a well drilling rig the combination of a drill string, a draw-works drum, a prime mover, a variable speed power transmission connected in driving relation between the prime mover and the draw-works drum, a. controlling member movable in accordance with variations in torque imposed on the drum by the drill string, a fluid motor for varying the speed ratio of the power transmission, means whereby said controlling member may control operation of said motor, and means eflective upon failure of said prime mover for bringing said power transmission string sustaining position.

EDWIN L. ROSE. FREDERICK S. HODGMAN to a drill 

